1. Field of the Invention
The present invention relates to an improved grip for an implement having a handle, and the method of manufacture of such a grip. The invention has particular utility in the manufacture of golf club grips.
2. Description of the Prior Art
Golf club grips and grips for other implements have a wide variety of different constructions and have been fabricated in different ways over the years. The shaft of a golf club is an elongated, narrow, generally cylindrical structure which may be formed of solid wood, a solid metal rod, or hollow metal tubing, closed at the end remote from the golf club head. The extremity of the shaft of the golf club remote from the head serves as a handle, and is usually no more than about five-eighths of an inch in diameter. The golf club shaft is typically quite smooth, so that a grip of some type on the handle end is essential to allow a golfer to control the swing of the club.
Conventional golf club grips are formed as hollow, elongated structures, often of a molded thermoplastic material. Golf club grips have an open end into which the handle is inserted, and an opposite end which is largely capped, but which usually has a small aperture therein to allow entrapped air to escape when the grip is pressed onto the golf club shaft handle.
Very frequently golf club manufacturers desire to have the name of their companies, or a trademark of other brand name emblazoned on the golf club grip. In the conventional fabrication of a golf club grip the desired indicia or other display is often painted on the outer, exposed surface of the grip. However, with use, portions of the paint very typically flake off so that the portion remaining presents an unsightly, unflattering appearance.
A need has existed for golf club grips in which surface displays will not wear off and become unsightly. My prior U.S. Pat. No. 5,261,665, hereby incorporated by reference in its entirety, discloses a system in which a golf club grip is formed in steps from sequential molded charges of thermoplastic materials having contrasting colors in which an inner socket is provided with an overlying outer jacket. The socket and jacket are formed of different charges of a thermoplastic, and the socket has a plurality of outwardly projecting portions that are laterally surrounded by the structure of the jacket, but which have exposed, display faces. During the molding process the display faces of the outwardly projecting portions of the inner socket structure reside in contact with the inner surface of the mold forming the overlying jacket. Consequently, the charge of thermoplastic material that forms the jacket, while laterally surrounding the projections from the inner socket, does not cover the display faces of the projections.
Golf club grips and other grips constructed in this manner can have mold configurations for the socket that produce any number of different display indicia that project through the jacket into which the socket is molded. Consequently, a wide variety of different displays can be produced utilizing the feature of my prior U.S. Pat. No. 5,261,665.
Golf club grips formed according to this prior patent are superior to golf club grips that have painted display indicia on their surfaces in that the color of the inner socket, including the outwardly directed projections, contrasts with the color of the jacket. As a consequence, letters, numbers, designs, and other displays can be provided on a such a grip and will not wear off or otherwise deteriorate with usage and with the passage of time.
However, even though the system produces a very superior product, there are certain manufacturing difficulties. Specifically, in this prior system a unique, separate mold is required to produce each socket having outwardly projecting display protrusions. Thus, while the same system can be utilized to produce comparable golf club grips for different manufacturers, wherein the name or trademark of each manufacturer is visible as a display, a separate mold is required for each different socket for each different manufacturer. Thus, to produce grips for a plurality of different manufacturers, a corresponding number of separate, unique socket molds are required.
Furthermore, in manufacturing grips for different manufacturers, the mold set up must be changed each time a run of grips for a different golf club manufacturer is to be produced. Changing of the molds is time consuming, as there are inevitably delays in adjusting and fine tuning the molding machinery each time a different socket mold is installed into the molding apparatus. The resulting downtime of the molding machinery increases the cost of production.
Furthermore, while the system of prior U.S. Pat. No. 5,261,665 is quite suitable for producing relatively large display features, it is incapable of producing displays having fine detail. That is, while complex figures and small numbers and letters can be painted on a golf club grip, it is quite difficult to fabricate a mold with projections that will produce fine detail on the surface of the grip.